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Parametrization and smooth approximation of surface triangulations
 Computer Aided Geometric Design
, 1997
"... Abstract. A method based on graph theory is investigated for creating global parametrizations for surface triangulations for the purpose of smooth surface fitting. The parametrizations, which are planar triangulations, are the solutions of linear systems based on convex combinations. A particular pa ..."
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Cited by 303 (12 self)
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Abstract. A method based on graph theory is investigated for creating global parametrizations for surface triangulations for the purpose of smooth surface fitting. The parametrizations, which are planar triangulations, are the solutions of linear systems based on convex combinations. A particular parametrization, called shapepreserving, is found to lead to visually smooth surface approximations. A standard approach to fitting a smooth parametric curve c(t) through a given sequence of points xi = (xi,yi,zi) ∈ IR 3, i = 1,...,N is to first make a parametrization, a corresponding increasing sequence of parameter values ti. By finding smooth functions x,y,z: [t1,tN] → IR for which x(ti) = xi, y(ti) = yi, z(ti) = zi, an interpolatory curve
Surface Parameterization for Meshing by Triangulation Flattening
 Proc. 9th International Meshing Roundtable
, 2000
"... We propose a new method to compute planar triangulations of triangulated surfaces for surface parameterization. Our method computes a projection that minimizes the distortion of the surface metric structures (lengths, angles, etc.). It can handle any manifold surface, including surfaces with large c ..."
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Cited by 33 (8 self)
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We propose a new method to compute planar triangulations of triangulated surfaces for surface parameterization. Our method computes a projection that minimizes the distortion of the surface metric structures (lengths, angles, etc.). It can handle any manifold surface, including surfaces with large curvature gradients and nonconvex domain boundaries. We use only the necessary and sufficient constraints for a valid twodimensional triangulation. As a result, the existence of a theoretical solution to the minimization procedure is guaranteed.
Code Optimizers and Register Organizations for Vector Architectures
, 1992
"... A major challenge facing computer architects today is designing costeffective hardware that executes multiple operations simultaneously. The goal of such designs is to improve performance by taking advantage of finegrain parallelism. In this dissertation, I study vector architectures, the oldest o ..."
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Cited by 20 (0 self)
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A major challenge facing computer architects today is designing costeffective hardware that executes multiple operations simultaneously. The goal of such designs is to improve performance by taking advantage of finegrain parallelism. In this dissertation, I study vector architectures, the oldest of several processor designs that support finegrain parallelism. Because implementing a costeffective processor that performs well requires studying not only the design of processors but also the design of algorithms for compilers, this dissertation encompasses aspects of both hardware and software design. In the first half of this dissertation, I demonstrate that a vector architecture is a costeffective processor that supports finegrain parallelism. I show that implementing a vector architecture is no more costly than implementing a superscalar architecture, which is currently popular among designers of VLSI microprocessors. I then show that programs that are rich in parallelism tend als...
STABILITY OF JACKSONTYPE QUEUEING NETWORKS, I
, 1999
"... This paper gives a pathwise construction of Jacksontype queueing networks allowing the derivation of stability and convergence theorems under general probabilistic assumptions on the driving sequences; namely, it is only assumed that the input process, the service sequences and the routing mechanis ..."
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Cited by 4 (0 self)
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This paper gives a pathwise construction of Jacksontype queueing networks allowing the derivation of stability and convergence theorems under general probabilistic assumptions on the driving sequences; namely, it is only assumed that the input process, the service sequences and the routing mechanism are jointly stationary and ergodic in a sense that is made precise in the paper. The main tools for these results are the subadditive ergodic theorem, which is used to derive a strong law of large numbers, and basic theorems on monotone stochastic recursive sequences. The techniques which are proposed here apply to other and more general classes of discrete event systems, like Petri nets or GSMP’s. The paper also provides new results on the Jacksontype networks with i.i.d. driving sequences which were studied in the past.
A Generic Approach to Free Form Surface Generation
, 2001
"... A theoretical approach to construct free form surfaces is presented. We develop the concepts that arise when a free form surface is generated by tracing a mesh, using differentiable manifold theory, and generalizing the Bspline scheme. This approach allows to define a family of practical schemes. F ..."
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Cited by 3 (0 self)
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A theoretical approach to construct free form surfaces is presented. We develop the concepts that arise when a free form surface is generated by tracing a mesh, using differentiable manifold theory, and generalizing the Bspline scheme. This approach allows to define a family of practical schemes. Four different applications of the generic approach are also presented in this paper.
Parameterization of Faceted Surfaces . . .
 ENGINEERING WITH COMPUTERS (2001) 17: 326337
, 2001
"... We propose a new method to compute planar triangulations of faceted surfaces for surface parameterization. In contrast to previous approaches that define the flattening problem as a mapping of the threedimensional node locations to the plane, our method defines the flattening problem as a constrain ..."
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We propose a new method to compute planar triangulations of faceted surfaces for surface parameterization. In contrast to previous approaches that define the flattening problem as a mapping of the threedimensional node locations to the plane, our method defines the flattening problem as a constrained optimization problem in terms of angles (only). After applying a scaling that derives from the `curvature' at a node, we minimize the relative deformation of the angles in the plane with respect to their counterparts in the threedimensional surface. This approach makes the method more stable and robust than previous approaches, which used node locations in their formulations. The new method can handle any manifold surface for which a connected, valid, twodimensional parameterization exists, including surfaces with large curvature gradients. It does not require the boundary of the flat twodimensional domain to be predefined or convex. We use only the necessary and sufficient constraints for a valid twodimensional triangulation. As a result, the existence of a theoretical solution to the minimization procedure is guaranteed.
P. A. Franasrek AddressIndependent Routing for Local Networks
"... A routing methodology is introduced which permits messages to be propagated throughout a network without recourse to destination or origin addresses. Two classes of networks, bidirectional trees and augmented rings, are analyzed from this point of view. An optimality property is proved for the bidir ..."
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A routing methodology is introduced which permits messages to be propagated throughout a network without recourse to destination or origin addresses. Two classes of networks, bidirectional trees and augmented rings, are analyzed from this point of view. An optimality property is proved for the bidirectional tree, and three types of addressindependent routing strategies are derived. It is shown that augmented loops, a class of structures incorporating redundant links, may be rerouted to compensate for the failure of any single node or link. 1.
The Application Of Word Image Matching In Text Recognition
"... Printed text recognition usually involves recognizing individual characters, and assembling the results to recognize words and sentences. However, the performance of conventional character recognition systems tends to suffer in the presence of moderate levels of degradation in the text. A method is ..."
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Printed text recognition usually involves recognizing individual characters, and assembling the results to recognize words and sentences. However, the performance of conventional character recognition systems tends to suffer in the presence of moderate levels of degradation in the text. A method is proposed that uses equivalence among frequent word images to derive hypotheses for each word using the available language statistics. Word images are clustered to determine equivalency. The attributes of the clusters, as well as the relationships among them are then matched with the same characteristics for the words in the language. The method requires no explicit training, and is fairly tolerant to image degradation. The results for several sample sizes are reported. 2 Contents 1 Introduction 4 1.1 Motivation : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 4 1.2 Problem Definition : : : : : : : : : : : : : : : : : : : : : : : : : : : : 5 1.3 This Thesis : : : : : : : :...
REPOT DCUMNTATON AGEREAD INSTRUCTIONS REPOT DCUMNTATON AGEBEFORE COMPLETING FORM
, 1978
"... i I I bhe rclcaH.bIe to the general public, including foreign nations. RAIJCTR784, Vol I (of two)has been reviewed and is approved for APPROVELD: t4I%)4 ALAN N. SIKRRT ..."
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i I I bhe rclcaH.bIe to the general public, including foreign nations. RAIJCTR784, Vol I (of two)has been reviewed and is approved for APPROVELD: t4I%)4 ALAN N. SIKRRT